The Swiss chiropractic practice-based research network: a population-based cross-sectional study to inform future musculoskeletal research

The Swiss chiropractic practice-based research network (PBRN) is a nationwide project developed in collaboration with patients, clinicians, and academic stakeholders to advance musculoskeletal epidemiologic research. The aim of this study was to describe the clinician population recruited and representativeness of this PBRN to inform future collaboration. A population-based cross-sectional study was performed. PBRN clinician characteristics were described and factors related to motivation (operationalised as VAS score ≥ 70) to participate in a subsequent patient cohort pilot study were assessed. Among 326 eligible chiropractors, 152 enrolled in the PBRN (47% participation). The PBRN was representative of the larger Swiss chiropractic population with regards to age, language, and geographic distribution. Of those enrolled, 39% were motivated to participate in a nested patient cohort pilot study. Motivation was associated with age 40 years or older versus 39 years or younger (OR 2.3, 95% CI 1.0–5.2), and with a moderate clinic size (OR 2.4, 95% CI 1.1–5.7) or large clinic size (OR 2.8, 95% CI 1.0–7.8) versus solo practice. The Swiss chiropractic PBRN has enrolled almost half of all Swiss chiropractors and has potential to facilitate collaborative practice-based research to improve musculoskeletal health care quality. Trial registration: Swiss chiropractic PBRN (ClinicalTrials.gov identifier: NCT05046249); Swiss chiropractic cohort (Swiss ChiCo) pilot study (ClinicalTrials.gov identifier: NCT05116020).


Introduction
Background/rationale 2 Explain the scientific background and rationale for the investigation being reported "Musculoskeletal (MSK) pain conditions, such as neck pain and low back pain, are a leading cause of disability globally and are the most prevalent disease area which would benefit from rehabilitation." "As a large proportion of MSK pain is managed in primary care, efforts to improve the quality of care in these settings, such as the development of practice-based research networks (PBRNs), may play an important role in identifying, studying, and addressing similar practice-based gaps." Objectives 3 State specific objectives, including any prespecified hypotheses "The overarching aim of this study is to describe the characteristics of chiropractors recruited to a newly developed Swiss chiropractic PBRN and the representativeness of the PBRN in comparison to the larger Swiss clinician population to facilitate subsequent collaborative practice-based research."

Study design 4
Present key elements of study design early in the paper "We reported this population-based cross-sectional study according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE for cross-sectional studies) statement." Setting 5 Describe the setting, locations, and relevant dates, including periods of recruitment, exposure, follow-up, and data collection "All 326 registered active chiropractor members (fully licensed chiropractors and postgraduate assistant chiropractors) of ChiroSuisse were eligible and invited to participate in the PBRN. This included members with clinical practice locations in Switzerland and Liechtenstein." "From September 9 th 2021 to December 19 th 2021, clinicians were provided the opportunity to sign up for the Swiss chiropractic PBRN through scanning a Quick Response (QR) code at an in-person ChiroSuisse event or through a web link via email invitation." Participants 6 (a) Give the eligibility criteria, and the sources and methods of selection of participants "All 326 registered active chiropractor members (fully licensed chiropractors and postgraduate assistant chiropractors) of ChiroSuisse were eligible and invited to participate in the PBRN. This included members with clinical practice locations in Switzerland and Liechtenstein."

Variables 7
Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if applicable "Primary clinical outcome of perceived self-confidence for the management of low back pain was measured using the Practitioner Confidence Scale ((PCS) range 4-20, lower scores mean greater self-confidence) and biomedical versus biopsychosocial treatment orientation was measured using the MSK version of the Pain Attitudes and Beliefs Scale (PABS-MSK, range 10-60 each, with higher scores meaning greater treatment orientation)." "The primary feasibility outcome of motivation to participate in the nested Swiss ChiCo patient cohort pilot study was measured using a Visual Analog Scale ((VAS), range 0-100), higher scores indicate greater motivation)."

Item
No Recommendation Data sources/ measurement 8* For each variable of interest, give sources of data and details of methods of assessment (measurement). Describe comparability of assessment methods if there is more than one group "Primary clinical outcome of perceived self-confidence for the management of low back pain was measured using the Practitioner Confidence Scale ((PCS) range 4-20, lower scores mean greater self-confidence) and biomedical versus biopsychosocial treatment orientation was measured using the MSK version of the Pain Attitudes and Beliefs Scale (PABS-MSK, range 10-60 each, with higher scores meaning greater treatment orientation)." "The primary feasibility outcome of motivation to participate in the nested Swiss ChiCo patient cohort pilot study was measured using a Visual Analog Scale ((VAS), range 0-100), higher scores indicate greater motivation). For this question, participants were asked "On a scale from 0-100 how motivated are you to participate in the patient cohort phase of the Swiss ChiCo pilot study".

Bias 9
Describe any efforts to address potential sources of bias "Clinicians were provided the opportunity to sign up for the Swiss chiropractic PBRN through scanning a Quick Response (QR) code at in-person ChiroSuisse event or through a web link via email invitation." "Before full implementation, the PBRN entrance questionnaire was pilot tested by licenced chiropractors from all Swiss national language regions (German, French and Italian Statistical methods 12 (a) Describe all statistical methods, including those used to control for confounding "Data were extracted from REDCap into R (version 4.2.0) for analysis. Descriptive statistics were reported as raw numbers with percentages or means with standard deviations as appropriate.
Primary clinical and feasibility outcomes were additionally described with 95% CIs for mean values and percentages. Multivariable logistic regression was used to assess the association between clinician and practice characteristics (age, sex, practice size, language of practice, EHR use) and motivation to participate in the patient cohort pilot study (Yes/No, cut point operationalised as VAS score ≥70). Alpha level was set at 0.05 and results were reported as odds ratios (ORs) with 95% CIs." (b) Describe any methods used to examine subgroups and interactions N/A (c) Explain how missing data were addressed "Only clinicians who completed the electronic informed consent and fully completed the entry questionnaire were considered as part of the PBRN and available for future nested study recruitment." (d) If applicable, describe analytical methods taking account of sampling strategy N/A (e) Describe any sensitivity analyses N/A

Results
Participants 13* (a) Report numbers of individuals at each stage of study-eg numbers potentially eligible, examined for eligibility, confirmed eligible, included in the study, completing follow-up, and analysed

Item
No Recommendation Descriptive data 14* (a) Give characteristics of study participants (eg demographic, clinical, social) and information on exposures and potential confounders "Clinician participants of this Swiss chiropractic PBRN enrollment cross-sectional study were generally balanced in terms of sex (53% male versus 47% female) with an average age of 47 years (SD=12.4). The majority were fully licenced chiropractors (87%), with the remainder being postgraduate chiropractors (13%)" "The most common language participating clinicians use in their practice was reported as German (69%), followed by French (25%), Italian (5%) and finally Romansh (1%)." (b) Indicate number of participants with missing data for each variable of interest "Only clinicians who completed the electronic informed consent and fully completed the entry questionnaire were considered as part of the PBRN and available for future nested study recruitment." Outcome data 15* Report numbers of outcome events or summary measures Of the 326 eligible chiropractors, 152 (46.6%) agreed to participate and completed the PBRN entrance questionnaire.
Main results 16 (a) Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (eg, 95% confidence interval). Make clear which confounders were adjusted for and why they were included "Independent variables included in the regression model were selected on the basis of clinical experience and prior analysis of factors related to EHR use for Swiss chiropractors." (b) Report category boundaries when continuous variables were categorized "A pragmatic decision was made a-priori to identify clinicians who reported a well above medium interest to participate in the Swiss ChiCo pilot study based on a VAS score of ≥70 (hereafter denoted as "motivated PBRN participants". (c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period Other analyses 17 Report other analyses done-eg analyses of subgroups and interactions, and sensitivity analyses N/A

Key results 18
Summarise key results with reference to study objectives "The project met pre-specified feasibility objectives of recruitment (approximately 50% of eligible clinicians) and showed an acceptable proportion of clinicians motivated to participate the nested patient cohort study (at least 15 members with a motivation score of ≥70). Forty-seven percent of eligible clinicians agreed to participate in the PBRN and 39% of the PBRN was motivated to participate in the nested patient cohort study. Participant clinicians showed high levels of perceived self-confidence in the management low back pain (measured with the PCS) and higher levels of biopsychosocial versus biomedical treatment orientation (measured with the PABS-MSK)."

Limitations 19
Discuss limitations of the study, taking into account sources of potential bias or imprecision. Discuss both direction and magnitude of any potential bias "Our study has several limitations. First, we only used an electronic data collection approach which may have led to selective participation of clinicians with higher levels of digital literacy." "Second, this Swiss Chiropractic PBRN study collected information through self-report and was subject to recall bias. Data quality may have been improved by asking clinicians to perform a chart review prior to completing the PBRN entry questionnaire." Interpretation 20 Give a cautious overall interpretation of results considering objectives, limitations, multiplicity of analyses, results from similar studies, and other relevant evidence "The Swiss chiropractic PBRN recruited approximately half of Swiss chiropractic clinicians in over one-hundred unique clinical practices across Switzerland. The PBRN is largely representative when comparted to the larger Swiss chiropractic population with regards to age, language, and location."

Item
No Recommendation Generalisability 21 Discuss the generalisability (external validity) of the study results "The Swiss chiropractic PBRN was proportionally more female and slightly younger than the larger Swiss chiropractic community. Of the participating clinicians, females and members practicing in large clinics were more likely to be motivated to participate in the patient cohort study"

Other information
Funding 22 Give the source of funding and the role of the funders for the present study and, if applicable, for the original study on which the present article is based "This work was internally supported at the University of Zurich through funding from the Foundation for the Education of Chiropractors in Switzerland. The funder had no role in the study conceptualization and design, or in the collection, analysis, interpretation of data, writing of the report or decision to submit the manuscript for publication."
[name_last], thank you for your participation in this study.
Questions on this survey will ask about clinician demographics, practice characteristics, clinician confidence in the management of low back pack pain, practitioner attitudes and beliefs towards MSK complaints, digitalization of chiropractic practices with regards to EPR and encrypted email use, and how COVID-19 has changed clinical practice.
All information is collected securely and kept confidential.

Types of patients and patient complaints seen within practice
Dr.
[name_last], from "often" to "never" please select the best option as it relates to the frequency of clinical complaints and the types of patients you see in practice 11. Frequency with each condition is managed in your practice Often Sometimes Rarely  Never  Neck pain without arm pain  Neck pain with arm pain  Neck pain with headache  Thoracic spine and rib pain  Low back pain without leg pain  Low back pain with leg pain  Shoulder

Pain attitudes and beliefs scale
Dr.
[name_last], we are interested in your views about non-specific musculoskeletal pain. Please indicate the extent to which you agree or disagree with the following statements about non-specific musculoskeletal pain by putting a tick in one box on each line. Please provide an answer to all the questions. If a question does not seem directly relevant to your clinical practice, please try to provide an answer based on your belief or instinct, rather than leave it blank

Digitalization of chiropractic clinics
Dr.
[name_last], the following questions relate to your use of electronic patient records and encrypted email use in practice 1. Do you use an electronic patient record (EPR) system for clinical record keeping in your practice? ▪ Yes. I use only an EPR system for clinical record keeping in practice ▪ Partially. I use a mix of an EPR and paper-based system for clinical record keeping in practice ▪ No. I use a paper-based system currently, but am considering switching to an EPR system